EXPERIMENTAL PRODUCTION OF ASCITES IN BROILER-CHICKENS USING INFECTIOUS-BRONCHITIS VIRUS AND ESCHERICHIA-COLI

Common commercial strain male broilers were intratracheally inoculated with 0.3 ml. of fluid containing 10(3.7) embryo infective doses of in fectious bronchitis virus (IBV) at 14 days of age and 7.5 x 10(6) colo ny-forming units of Escherichia coli at 18 days of age. Ascites was de tected in 15 out of 100 infected birds, which was significantly higher than in a control group of 100 mock-infected birds (P < 0.01). Some p arabronchi were blocked by copious exudate containing heterophils and fibrin in tile infected birds at 22 days of age although these finding s were not seen in the infected birds at 35 days of age or in birds wi th ascites. The erythrocyte packed cell volume and right ventricle/tot al ventricle (RV/TV) ratio of birds with ascites were higher than in b irds without ascites. The RV/TV weight ratio far tile infected group a t the age of 35 days was higher than that of the control group. No IBV or E. call were recovered from the ascitic birds. These findings sugg est that these infectious agents induce ascites in the broilers, and t hen disappear until the birds suffer from ascites.